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United States Patent | 5,074,530 |
Iwasaki ,   et al. | * December 24, 1991 |
The invention provides an apparatus for smelting reduction of iron ore which contains (1) at least one preheat and prereduction furnace which preheats and prereduces iron ore to a prereduction degree of less than 30%; (2) a smelting reduction furnace into which the preheated and prereduced iron ore, carbonaceous material and flux are charged and in which the preheated and prereduced iron ore is reduced; and (3) a top blow oxygen lance having first nozzles for decarburization and second nozzles for post-combustion, oxygen gas being blown through the first nozzles and the second nozzles into the smelting reduction furnace. At least one side tuyere is placed in a side wall of the smelting reduction furnace and at least one bottom tuyere is placed in a bottom wall of the smelting reduction furnace for blowing a stirring gas through the at least one side tuyere and the at least one bottom tuyere into the smelting reduction furnace.
Inventors: | Iwasaki; Katsuhiro (Tokyo, JP); Takahashi; Kenji (Tokyo, JP); Inoue; Shigeru (Tokyo, JP); Tanabe; Haruyoshi (Tokyo, JP); Kawakami; Masahiro (Tokyo, JP); Terada; Osamu (Tokyo, JP) |
Assignee: | NKK Corporation (Tokyo, JP) |
[*] Notice: | The portion of the term of this patent subsequent to June 26, 2007 has been disclaimed. |
Appl. No.: | 599679 |
Filed: | October 17, 1990 |
Dec 18, 1987[JP] | 62-322321 | |
Dec 18, 1987[JP] | 62-322322 | |
Dec 18, 1987[JP] | 62-322328 |
Current U.S. Class: | 266/157; 266/172; 266/175 |
Intern'l Class: | C21C 005/40 |
Field of Search: | 266/157,172,176,186,175,182 |
3711275 | Jan., 1973 | Johnsson | 75/40. |
4504311 | Mar., 1985 | Weiner | 266/219. |
4936908 | Jun., 1990 | Takahashi et al. | 75/502. |
Foreign Patent Documents | |||
58-144407 | Aug., 1983 | JP | 75/38. |
61-43406 | Sep., 1986 | JP. |